The invention relates in general to slapper detonators and in particular to a mechanically lockable interrupt for the high voltage generator section of a slapper detonator/exploding foil initiator (SD/EFI).
Fuzing/SafetyandArming (F/SandA) systems are required to meet the fail-safe requirements of MILSTD 1316D. MILSTD 1316D sets forth the requirements for acceptable designs. Historically, the requirements have been met by the use of explosive barriers and/or an out-of-line explosive train that are held in the safe position by mechanical locks. When the mechanical locks are removed, the explosive train can be aligned (Arm mode) and is able to respond to a detonation command.
Explosives can also be detonated by using Exploding Foil Initiators (EFI) or Slapper Detonators (SD). In these devices, a high voltage and current is applied to the EFI/SD to initiate the explosives. They are commonly referred to as Electronic Safety and Arming Devices (ESAD). They are an in-line explosive train and do not contain any mechanical locks. They have been approved for certain limited applications. Universally acceptable designs that have met all the intention (including immunity from single point failures) of MILSTD 1316D are still evolving.
MicroElectroMechanical Systems (MEMS) is a technology that is an outgrowth of the integrated circuit (IC) industry. It employs many common design and fabrication techniques. Whereas the IC industry produces electrical devices, MEMS can also produce mechanical mechanisms on the micron scale. Because the mechanical devices are on the micron scale (10xe2x88x926), movement/forces produced are also on the micron scale (10xe2x88x926). It is difficult to move conventional macro devices (explosives/barriers) with microactuators. Since a light beam exerts no force on reflectors, it is compatible with MEMS. Combining optical circuits (fiber optics and laser diodes) and MEMS (movable reflectors) offers a unique opportunity to build MEMS systems that meet the requirements of MILSTD 1316D by using mechanically lockable devices.
In accordance with the invention a safe/arm apparatus comprises a slider barrier having at least one notch formed therein, the slider barrier including an optically diffuse surface and an optically reflective surface; at least one mechanical lock removably disposed in the at least one notch; a linear actuator for moving the slider barrier from a safe position to an armed position; a battery; a laser diode connected to the battery, the laser diode emitting a light beam towards the optically diffuse surface when the slider barrier is in the safe position and towards the optically reflective surface when the slider barrier is in the armed position; a photodiode for receiving light reflected from the optically reflective surface; a transformer connected to the photodiode; and a capacitor connected to the transformer.
In a preferred embodiment, the slider barrier includes a second notch formed therein, the apparatus further comprising a second mechanical lock removably disposed in the second notch.
Another embodiment of the invention is a safe/arm apparatus comprising a slider barrier having at least one notch formed therein, the slider barrier including first and second optically reflective surfaces; at least one mechanical lock removably disposed in the at least one notch; a linear actuator for moving the slider barrier from a safe position to an armed position; a battery; a laser diode connected to the battery, the laser diode emitting a light beam towards the first optically reflective surface when the slider barrier is in the safe position and towards the second optically reflective surface when the slider barrier is in the armed position; a light trap for receiving light reflected from the first optically reflective surface; a photodiode for receiving light reflected from the second optically reflective surface; a transformer connected to the photodiode; and a capacitor connected to the transformer.
Another aspect of the invention is a safe/arm apparatus comprising a motor; a rotor connected to the motor, the rotor having at least one notch formed therein, the rotor including an optically diffuse surface and an optically reflective surface; at least one mechanical lock removably disposed in the at least one notch; a battery; a laser diode connected to the battery, the laser diode emitting a light beam towards the rotor; a photodiode for receiving light reflected from the optically reflective surface when the rotor is in an armed state; a transformer connected to the photodiode; a rectifier connected to the transformer; and a capacitor connected to the rectifier.
In another embodiment of the invention, a safe/arm apparatus comprises a motor; a rotor connected to the motor, the rotor having at least one notch formed therein, the rotor including a first optically reflective surface and a second optically reflective surface; at least one mechanical lock removably disposed in the at least one notch; a battery; a laser diode connected to the battery, the laser diode emitting a light beam towards the rotor; a photodiode for receiving light reflected from the first optically reflective surface when the rotor is in an armed state; a light trap for receiving light reflected from the second optically reflective surface; a transformer connected to the photodiode; a rectifier connected to the transformer; and a capacitor connected to the rectifier.
The invention also includes a method of arming a fire set comprising removing at least one mechanical lock from a notch in a slider barrier; moving the slider barrier to an armed position; directing light to an optically reflective surface of the slider barrier; receiving light reflected from the optically reflective surface with a photodiode; converting the received light to electricity; transforming the electricity to a higher voltage; and storing the higher voltage electricity in a capacitor.
Yet another aspect of the invention is a method of arming a fire set comprising removing at least one mechanical lock from a notch in a rotor; rotating the rotor; directing light to the rotating rotor; receiving light reflected from an optically reflective surface of the rotor with a photodiode; converting the received light to electricity; transforming the electricity to a higher voltage; rectifying the higher voltage electricity; and storing the higher voltage electricity in a capacitor.
Further objects, features and advantages of the invention will become apparent from the following detailed description taken in conjunction with the following drawings.